Pleurotus AGARICACE/E 93 



420. P. mutilus Gill, (from its being changeable in form ; 



maimed) a c. White. 

 P. excentric, lateral, reniform or spathulate, depressed, silky- 



smooth. St. excentric or lateral with a villous base. 

 Dead wood, rotting elm, fir-plantations, on a grassy hillside. Aug.-Dec. 



i| x X & in. Might be mistaken for a small Clitocybe. Sometimes 



appears on mushroom-beds. 



421. P. ostreatus Quel. (from the shape and colour of the pileus ; 



ostrea, an oyster) a b c. 



P. convexo-depressed, subexcentric, slate or brownish, when 

 young sometimes almost black. St. connate-branched, excen- 

 tric, rarely central, sometimes obsolete, white. G. reticulate 

 below, whitish. 



Crespitose-imbricate. Said to be edible. Odour strong. Trunks and logs, 

 elm, poplar, walnut, beech, laburnum, apple, Wistaria; once on dry 

 cerebral matter in skull of a stranded whale. Jan.-Dec. 4 x 2 x in. 

 Var. colnmbiniis Quel. has a purplish pileus and bluish or greenish marg. 

 Var. glandiilosus Mass, has tear-like drops on the gills. 



422. P. euosmus Sacc. (Gr. euosmus, sweet-smelling) a b c. 



P. convexo-depressed, tan to olivaceous-brown. St. varying 



long, short or obsolete. G. reticulate below. Spores tan, 



lilac or salmon-shaded. 

 Ccespitose-imbricate. Said to be poisonous. Odour of tarragon. Stumps, 



logs, poplar, elm. April-Oct. 5i X 3^ X i in. Intermediate forms 



between this and 421 occur. 



423. P. revolutus Gill, (from the ultimately revolute margin of the 



pileus) a. 

 P. plane, smoky, lead- or mouse-colour; mid. darker. St. 



whitish. G. serrulate, whitish. 

 Solitary or subcaespitose. Trunks, poplar, beech. Autumn. ioix2^X2in. 



424. P. salignus Quel. (from one of its habitats ; Salix, willow) a b c. 

 P. pulvinate, plane, ochreous, smoky slate-colour or almost black. 



St. almost obsolete, tan. Spores dull whitish. 



Solitary, rarely ctespitose or imbricate. Trunks, willow, ash, elm, sycamore, 

 alder. Sept.-Feb. Si X 5 X if in. 



425. P. aeerinus Gill, (from one of its habitats ; Acer, maple) a b. 



White. 

 P. tough, fleshy, thin, silky-villous, pale rufous when dry. St. 



sublateral or obsolete, villous. G. very crowded, thin, white 



then yellow ; livid-vinous when dry. 

 Trunks, maple, ash, plane. Autumn. 3 x ij X I in. 



b. Dimidiates. 



426. P. petaloides Quel. (from a fancied resemblance to a leaf; 



(jT.petalon, a leaf, eidos, appearance) a b c. 



P. plane, subumbonate, fuscous, brown, ochreous or purplish. 

 St. sublateral, villous, whitish. G. decurrent, white, yellowish 

 or ashy. 



Gregarious, caespitose or imbricate. Taste bitter. Terrestrial and on stumps, 

 pine ; rare. Aug. -Jan. 3f X i X I in. 



